The cable or the like protection and guide device comprises link bodies flexibly connected to adjacent link bodies. The front end of each link body is flexibly connected to the respective rear end of an adjacent link body. One end of the cable or the like protection and guide device is attached to a movable machine and the other end thereof is attached to a fixed frame or a floor surface. Each link body has a hollow space inside the link body. Further, a flexible body such as a cable, a hose, or the like is accommodated in the hollow space of the continuous link bodies. Energy is supplied to the movable machine from the floor surface.
One example of the cable or the like protection and guide device comprises a plurality of flexibly connected link bodies. Each link body has a pair of right and left link plates, a connecting arm, and an opening/closing arm. Sometimes herein the right link plate is referred to as one link plate and the left link plate is referred to as the other link plate or “another link plate”. The connecting arm connects the respective lower edges of the link plates. The upper portion of one of the link plates of each link body includes a hinge pivotably connected to a first end of the opening/closing arm.
An engagement pin is provided in an upper portion of the other link plate. The engagement pin is engageable with an engagement piece on the second end of the connecting arm. The engagement pin extends in the longitudinal direction of the chain. The chain is located in the hollow space inside of the connected link bodies. An engagement piece inserts into and is slidably movable along the opening/closing arm. One end of the engagement piece slidably interconnects with the second end of the opening/closing arm. The other end of the engagement piece has an engagement pin insertion groove which extends in the longitudinal direction of the link plate. The first end of the opening/closing arm is pivoted about an end of the hinge which resides in the upper portion of the link plate. The engagement piece is movable along the opening/closing arm so that the engagement pin may be engaged with the engagement pin insertion groove. See for example Patent Reference 1. Patent Reference 1 is Japanese Patent Publication No. 3356699.
Problems to be Solved by the Invention
In a conventional cable or the like protection and guide device, an upper end portion of a link plate and the end of an opening/closing arm are fixed to each other by an engagement structure. The engagement structure consists of an engagement pin insertion groove in an engagement piece movable along the opening/closing arm. As a result when both elements are not reliably fixed to a required engagement position due to insufficient positioning there are problems. One serious problem that may occur is the easy disengagement by vibration or the like during operation. This can lead to a serious failure in engagement. Further, when members forming the engagement structure break, the other end of the opening/closing arm cannot be fixed to the upper end portion of the other link plate and the opening/closing arm is separated. Additionally, when the engagement piece that is movable along the opening/closing arm is lost, the opening/closing arm is not used.
Further, when an upper end portion of the other link plate and the other end of an opening/closing arm are fixed to each other by only one engagement structure such as an engagement pin insertion groove in an engagement piece other problems may occur. For example, when the cable (or the like) is heavy, the large load applied to the engagement structure can result in significant loss of endurance throughout the entire structure. Further, there is a problem that the size of the engagement structure has limitations due to strength requirements. As a result, miniaturization of the entire device with sufficient strength cannot be achieved.
Accordingly, the object of the present invention is to solve the above-mentioned problems and to provide a cable or the like protection and guide device in which inadvertent disengagement during operation can be avoided by making the engagement between an opening/closing arm and link plates reliable and strong. It is an additional object of the invention to provide a structure with a dual locking mechanism. Easy engagement operation and excellent endurance are achieved.